Electron pockets and pseudogap Dirac point in underdoped cuprate superconductors

¹ Department of Physics, University of Guelph - Guelph, Ontario, Canada N1G 2W1
² Guelph-Waterloo Physics Institute, University of Guelph - Guelph, Ontario, Canada N1G 2W1
³ Department of Physics and Astronomy, McMaster University - Hamilton, Ontario, Canada L8S 4M1
⁴ The Canadian Institute for Advanced Research - Toronto, Ontario, Canada M5G 1Z8

^a enicol@uoguelph.ca

Received: 11 May 2011
Accepted: 28 June 2011

Abstract

We consider a model of the pseudogap specifically designed to describe the underdoped cuprates and which exhibits particle-hole asymmetry. The presence of electron pockets, besides the usual hole pockets, leads to the appearance of new vectors beyond the usual so-called octet model in the joint density of states (JDOS), which underlies the analysis of Fourier-transform scanning tunneling spectroscopy (FT-STS) data. These new vectors are associated with distinct patterns of large amplitude in the JDOS and are expected to occur primarily at positive bias. Likewise a pseudogap Dirac point occurs at positive bias and this point can be determined either through FT-STS or through extrapolation of data from the autocorrelation function of angle-resolved photoemission spectroscopy.